Microcomputer-assisted systems for recording and control of growing phytoplankton cultures

This report describes a basic unit for microcomputer-assisted recording of the turbidity of phytoplankton cultures. The unit is applied in several experimental systems for single and multiple batch and dilution cultures in combination with different types of control functions. These applications include: (i) single batch cultures with double-beam recording, temperature compensation, manual or automatic dilution and sampling; (ii) a multiturbidometer designed to record the growth of 16 batch cultures simultaneously; and (iii) a triple cage-culture turbidostat system. Selected examples of application with Skeletonema costatum have also been included to illustrate some of the possibilities of such microcomputer-assisted systems. These examples include studies of ultradian growth rhythms, toxicity testing and light–shade adaptation.